Four-thousand-year-old genomes show deep roots of social inequality

In a first-of-its-kind study, scientists have used ancient DNA to reconstruct the family trees of dozens of individuals who lived in a small German valley around 4,000 years ago. The genealogies point to social inequality within individual households, which encompassed both high-status family members and unrelated, low-status individuals — possibly servants or even slaves — as well as mysterious foreign females related to no one else.